In a conventional data center, a large number of servers and multiple storage apparatuses are coupled via a fibre channel (FC) interface. For example, a server, a network apparatus or a storage apparatus may be replaced with a new apparatus, a new apparatus may be added, or an old apparatus may be removed from the computer system due to a degrade in apparatus performance, the end of apparatus service life, a shortage of apparatus capacity, a shortage of network bandwidth, or the scaling up of a system.
In conventional server virtualization technology, multiple virtual machines can be operated by running virtualization software on a physical server. In this server virtualization technology, a virtual machine, which is running on one physical server, can be temporarily suspended, and migrated to the virtualization software running on another physical server. Management operations according to the addition, replacement or removal of a server are implemented using this technology.
As described above, in the prior art, it is possible to run multiple virtual machines on a physical server. In order to operate a virtual machine that is running on one physical server on another physical server, it is preferable to virtualize a fibre channel port so as to enable the FC port to also be migrated in terms of virtual machines. Accordingly, a technology (NPIV: N_Port Identifier Virtualization) for virtualizing the name of an FC node port (N_Port), which is an FC protocol expansion technique, is used. It is possible to migrate an FC port in virtual machine units by using a switch and host bus adapter (HBA) corresponding to NPIV.
In NPIV, it is preferable not to change the name identifier (WWPN: World Wide Port Name) allocated to a virtual node port (VN_Port) between the pre-migration server WWPN and the post-migration server WWPN. The reason for this will be explained. A zoning function, which is an FC switch security function, implements access control using either the WWPN, which is the name identifier of the N_Port, or a N_Port ID, which is calculated from either an FC switch domain number or a physical port number. When the FC switch zoning changes, a configuration change of the entire change-targeted fabric occurs, temporarily suspending IO (Input/Output) of all other N-Ports unrelated to the zoning setting target N_Port. Therefore, the greater the increase in the number of switches (number of domains) or the number of nodes that belong to the fabric, the longer the IO suspension time. For this reason, the zoning setting cannot be easily changed in a large-scale FC fabric configured using multiple FC switches.
Furthermore, there are two types of FC zoning. The one is based on a Port identifier (N_Port ID), and the other is based on the name identifier (WWPN). In a case where the Port identifier-based zoning is used, the zoning must always be changed in a virtual machine migration. The reason for this is because the N_Port ID always changes when a virtual machine is migrated to another physical server, and frame transfer related to a post-migration virtual machine is not allowed by the zoning function based on the FC switch Port identifier. Therefore, in order to implement the migration of a virtual machine across physical computers using server virtualization technology, the user managing the computer system must implement settings that base the FC port zoning function on WWPN. The user passes on the same WWPN as the pre-migration WWPN to the VN_Port (NPIV virtual N_Port) before and after the virtual machine migration. In doing so, the user is able to migrate the virtual machine to another physical server without changing the FC switch WWPN-based zoning setting at all.
In the past, most network equipment was configured redundantly. In a redundantly configured network, subsequent to replacing network equipment (an FC switch or the like) of the one system with new network equipment, it is possible to replace the network equipment of the other system with new network equipment as well. Due to this, it is possible to achieve a network with higher performance and/or higher bandwidth.
In a storage addition operation or migration operation as well, it is conceivable that the user is able to migrate a storage without changing the FC switch zoning setting by having a function in which the destination storage N_Port assumes the WWPN of the source storage the same as in the migration of the server virtual machine. However, there have been no disclosures with regard to technology related to the problem of IO processing suspension time becoming longer in accordance with the FC switch processing time ([Patent Literature 1]).
Furthermore, in conventional FC, there is a Virtual Fabric (VF) and technology for routing between Virtual Fabrics. The Virtual Fabric is technology for minimizing the scope of Zoning changes. Specifically, it is similar to Ethernet (registered trademark) virtual LAN (VLAN: Virtual Local Area Network) technology, and is technology for minimizing the extent of the impact of IO suspension in accordance with topology changes and setting changes of another fabric by logically dividing the FC fabric. Also, since virtual fabrics are not able to communicate with one another when virtual fabrics are used, an Inter Fabric Router (IFR) has been standardized as technology for implementing routing between virtual fabrics for the purpose of communicating between virtual fabrics. However, since zoning information is also sent and received between fabrics and the zoning settings change from one fabric to the other when different fabrics are coupled via a router, the extent of the impact on IO suspension increases in accordance with the zoning changes ([Patent Literature 2], [Non-patent Literature 1]).